Shock absorber



sept- 1, 1936- D. B. D. BLAKE Re. 20,084

SHOCK ABSORBER Original Filed May 25, 193D Reissued Sept. 1, 1936 SHOCK ABSORBER Dennis B. D. Blake, Danville, Ill., assignor,'by direct and mesne assignments, to General Mo tors Corporation, Detroit, Mich., a corporation of Delaware Original No. 1,890,311, dated December 6, 1932, Serial No. 454,895, May 23, 1930. Application for reissue January 2, 1934, Serial No. 704,986

34 claims. (cl. 18s-rss) My invention relates to shock absorbers of the hydraulic type for vehicular adaptation and is concerned more particularly with devices of this nature which are arranged to interpose a predetermined braking resistance to the yielding and rebound movements cfa spring as the vehicle moves over a roadway, the resistance offered being preferably less for the yielding than for the rebound movement and the parts being susceptible of calibration to establish any desired ratio of these resistances.

One object of the invention is to devise a shock absorber of the character described in which the valving of the liquid to control its flow in opposite directions is accomplished by valve members in the form of disks having designated shapes and arrangement of openings, the nature of the disks being such that a single disk may be employed under vgiven conditions, or two disks placed in cooperative relation with coacting sets of openings to achieve the desired control, or under other conditions, the valving may be effected by a cooperative group comprising the single disk disposed Viin spaced relation to the two coacting disks.

A further object is to devise a shock absorber as above described which is characterized by a valving arrangement which may be readily modified to meet a variety of operating conditions, and is further featured by a simplicity in design which is reflected in low manufacturing and maintenance costs.

These and further objects of my invention will be set forth in the following specification, reference being had to the accompanying drawing, and the novel means by which said objects are l effectuated will be definitely pointed out in the claims.

In the drawing:

Figure 1 is a plan view of one form of my improved shock absorber as it appears in use on a vehicle.

Fig. 2 is an enlarged section along the line 2-2 in Fig. 1, looking inthe direction of the arrows.

Fig. 3 is a perspective view showing the valve members, slightly spaced from each other, which are utilized to control the flow of fluid during the rebound action of the spring.

Fig. 4 is a perspective view of the Valve member vat the opposite end of the shock absorber which controls the fluid flow during the yielding movement of the vehicle spring.

For purpose of illustration, my improved valve members, which constitute the principal feature of the present invention," areshown in a shock absorber of the double acting type and in an arrangement comprising afpair of such membersl disposed at one point in-the absorber and a single 5f valve member disposed in another, the three valve members cooperating to achieve the desired controll onv the fluid duringv the operation of the device. However, it will be understood that,Y under certainv conditions, only fa single member may beemployed, whileunder other circumstances, only the two, immediately coacting members may be employed alone as a group.

Referring to Fig. 1, the numeral I0 designates the type of shock absorber shown,which comstuds I1 may be usedto attachthe casing II :to

a convenient portion of the vehicle chassis.

Rotatably mounted within 'the j-portion vI4 in journals I8-l formed on opposite sides. thereof, is a rock shaft I 9 which extends forwardly ofan'd through the casing I I for attachmenton the outside thereof to one end of .a lever 2B, the opposite end of which may be suitably fashioned for attachment to any desire-d type of linkage or otherv connecting feature, whereby the-lever 20 may be actuated from the axle.- Intermediate the journals IS-IB, the shaft I9 has secured thereto a lever 45 by means of a plug-2l andthe lower end of vsaid lever extends downwardly within the lower portion'of the casing I I vandvis suitably rounded, or ball-shaped, as at 2| for reception Within a similarly shapedsocket 22 provided in a piston 23.' The piston 23 extends in opposite directions from the lower end of thelever 20 and the opposite ends of said piston define with the adjacent 'ends of the casing'v Il'- brake chambers 24 and 25, respectively, the space within the 'vertical portion I4 above the piston serving as a' reservoir for the braking fluid. l f

As viewed in Fig. 2, the right end of the piston 23 is provided with a bore 21-which is coaxial with the longitudinal axis of said piston i and which extends inwardlyfrom the right end thereof for a predetermined distance. Similarly, the left end of said piston is Vprovided Vwith a' bore 28 which is also coaxial rwith the longitudinal bore 0f said piston and extends inwardlyfor alpredetermined distance from said end. The bores 21 and 28 are placed in communicating relation by means of a passage 29 having a smaller diameter than either of said bores and Whose junction with the bore 21 defines a shoulder 30 and. with the bore 23 a shoulder 46.

Seated against the shoulder 30 is a valve disk 3| having within the margin thereof a flap 32 which is connected to the remainder of the disk byf a segment 33 and separated at all other points by a parti-annular slot 34, the width of the segment 33 being only sufficient to connect `said flap to the remainder of the disk, but without disturbing its capacity for being moved out of the plane of said disk as hereinafter described. The flap 32 has sufficient diameter to also seat against the shoulder 3|| and is provided with a central, restricted aperture 35 for a purpose hereinafter explained, said aperture being preferably coaxial with the longitudinal axis of the piston 23 and accordingly with that of the passage 29. One end vof a coil spring 36 is always in engagement with one lside of the disk 33 exteriorly of the :parti-annular slot 34 for the purpose of maintaining :said disk against .the shoulder 39, and at the :opposite end of said spring, the outer coil 3'| is slightly enlarged iin diameter yfor Alocking reception within an annular groove 38 provided in the Lbore 2T.

.Seated against the shoulder 46 is la disk 39 having 'a pair of segmental passages 40 extending `theretlirougli and separated by a strip 4I, the distance between 4the remote sides of the passages across the width of said strip being preferably not greater than the diameter of the passage 29 for a purpose hereinafter explained, andthe width of said strip being larger than the diameter oi the aperture 35. A disk 3| is seated against the outer face of the disk 39 and both .of said disks are retained in the position shown in Fig. 2 'by the inner end of -a coil spring 42 whose outer lcoil 43 is yslightly enlarged in diameter for locking reception within an annular groove 44 provided vin the .bore 23. It is contemplnted that the disks 3| and 39 will be formed of sheet metal having sufllcient resiliency so lthat the iiap 32 may, when actuated by suf- .cient pressure, bend out of the plane of the disk 3| and, when said pressure is removed, will resume its normal position. Similarly, the strip 4 I will have sumcient resiliency to bow slight- .ly out of the plane Yoi* the disk 39 when actuated `by Va pressure :operating through the adjacent aperture 35 and tn return to its normal position when Isaid pressure is removed.

In discussing the voperation of my improved 'shock absorber, it will be Iassumed that the reservoir 26 'and the brake chambers 24 and 25 are 'lled with an adequate supply of fluid. When 'the vehicle is at rest or moving along a substantially level roadway, the lever 20 and accordingly the piston 23 will occupy the symmetrical posi- .tion shown in Figs. l and A2, but when a wheel of the vehicle vhas dropped into .a hole or has ridden Yovera raised yportion of the roadway, the accompanying movement of the axle, Vto which the end of the lever 20 is connected, rin conjunction with the weight of and load on the vehicle, will cause a yielding movement of the spring and a consequent actuation of the ball end 2| of the lever 20 in a counterclockwise direction, thus moving the piston 23 toward the right, as viewed in Fig. 2. This movement of the piston 23 creates a definite-pressure on the fluid within the chamber .24, dependent upon the speed of the movement,

and the pressure so established seats the iiap 32 against the shoulder 30 to thereby cause a restricted flow of some extent through the aperture 35 into the passage 29. At the left end of the piston 23, the fluid pressure in the passage 29 operating through the openings 49 will cause a movement of the adjacent flap 32 away from contact with the. disk 39, thereby providing for a relieving flow of the fluid into the brake chamber 25.

Upon the completion of the yielding movement of the spring, the rebound movement of the same, which is more violent than its initial displacement, must accordingly be restrained to a greater extent than that necessary during the yielding movement. Under these conditions, the piston 23 is actuated toward the left, as viewed in Fig. 2, so that the pressure established in the braking chamber 25 immediately seats the flap 32 of the left hand disk 3| against the disk 39, thereby closing the openings in said disks and confining the flow to that obtainable through the aperture 35 in vthe left hand disk 3|, which is covered by the resilient strip 4|. This strip accordingly bows out of the pla-ne of the disk 39 toward the right, as viewed in Fig. 2, a sufcient'amount to permit a iiow through said aperture, dependent upon the speed of movement of the piston 23. At the right end of the piston 23, the pressure in the passage 29 moves the flap 32 ltowards the right to provide for a relieving W- through the right disk 3|.

From the foregoing, it will be understood that, during the yielding movement of the spring, the

resistance offered by the shockabsorber isthat obvtainable by the resistance offered to the passage of the iiuid from the brake chamber 24 through the aperture 35, this aperture being susceptible of calibration to provide any degree of resistance, dependent upon the operating conditions. ing the rebound movement of the spring, the resistance offered is that obtained by a confinement of the flow through the left hand aperture 35 as restricted by the resilientstrip 4|, and this aperture, as Well as the resilience of the strip 4| may be arranged to give any desired braking eiect.

It is considered to be Within the range of the present invention to not only employ the valve disks 3| and 39 in the manner above described,

but that a single valve disk 3| maybe employed to control the fluid flow by .suitably Calibrating the aperture 35. Likewise, it is deemed .possible to employ the grouping of the two disks 3| and 39, as shown at the left end of the piston 23, to handleother types of braking resistances, so that no restrictive interpretation is to ybe placed upon the arrangement of valve disks which has been more particularly described above.

One of the most important advantages of a shock absorber construction which utilizes a valving arrangement as above described is that the operation of the device is substantially independent of any changes which may occur in the viscosity of the oil or other liquid which may be used as the braking medium. These changes are brought about by climatic variations in temperature and also to some extent by the frictional heating due to the movement of the shock absorber parts and the movement of the liquid. Under these conditions it is desirable that the effective areas of the ow controlling ports be susceptible of variation according to the varying pressures which may obtain in the shock absorber at anygiven time due to changes in the viscosity Durof the liquid. It will be readily understood that this desirable result can be attained by the use of the valve discs noted above, as the extent of deflection of their movable parts varies directly with the degree of pressure operating thereagainst.

While I have shown one set of elements and combinations thereof for eiectuating my improved shock absorber, it will be understood that the same is intended for purpose of illustration only and in no-Wise to restrict my device to the exact forms and structures shown, for many changes may be made therein Without departing from the spirit of my invention.

I claim:

1. In a fluid flow shock absorber, the combination of a support having a passage therethrough, and a valve disk associated with said support having a flap cut from said disk within the margin thereof and joined to said disk by a connecting segment, said flap having an opening therethrough and movable out of the plane of said disk by a fluid pressure established on one side of said support to permit a ilow through said passage and seated against said support by a iluid pressure established on the opposite side thereof to permit a smaller flow through said opening.

2. In a fluid flow shock absorber, valve means comprising a pair of cooperating disk members, one of said members having a yieldable portion provided with a restricted opening therethrough and the other of said members being cut out within its margin to provide a passage therethrough larger than said restricted opening and a yieldable strip bridged between the opposite sides of said passage to cover said restricted opening, said yieldable portion being movable by a fluid pressure established on one side of said valve means operating thro-ugh said passage to permit a flow therethrough and returned by a fluid pressure established on the opposite side of said valve means to permit a smaller flow through said restricted opening against the resistance offered by said yieldable strip.

3. In a iiuid ilow shock absorber, valve means comprising a pair of cooperating valve disks, one of said disrs having a flap cut from said disk Within the margin thereof and joined to said disk by a connecting segment, said ap having a restricted opening therethrough, and thevother of said disks being cut out Within its margin to provide a passage therethrough larger than said restricted opening and a yieldable strip bridged between the opposite sides of said passage to cover said restricted opening, said flap being movable out of the plane of its disk by a uid pressure established on one side of said disk operating through said passage to permit a flow therethrough and seated in the plane of its disk by a fluid pressure established on the opposite side of said disk to permit a smaller flow through said restricted opening against the resista-nce offered by said yieldable strip.

4. In a fluid flow shock absorber, the combination of a valve disk having an opening bridged by a yieldable strip, a second valve disk cooperat` ing with said first valve disk and having a flap covering said opening and a restricted opening cover-ed by said strip, said ap opening to permit flo-W in one direction and closing in the opposite irection to conne the flow through said restricted opening against the resistance offered by said strip.

5. In a uid flow shock absorber, the combination of a resilient metal valve disk having an opening bridged by an integral, yieldable strip, a second resilient metal valve disk cooperating with said first valve disk Vand having an integral flap covering said opening and a restricted opening covered by said strip, said flap opening to permit flow in one direction and closing in the opposite direction to confine the flo-W thro-ugh said restricted opening against the resistance offered by said strip.

6. In a fluid flow shock absorber, the combination of a casing, a piston having an opening therethrough reciprocable in said casing, and a valve disk having a yieldable flap covering said piston opening with a restricted opening disposed within the margin of said flap, said flap opening to permit flow in one direction and closing in the opposite direction to conne the iloW through said restricted opening.

'7. In a fluid flow shock absorber, the co-mbination of a casing, a piston having an opening therethrough reciprocable in said casing, a valve disk having an opening bridged by a yieldable strip, said disk opening communicating with said piston opening, a second valve disk cooperating with said rst valve disk and having a ap cov-- ering said rst disk opening and a restricted opening covered by said strip, said flap opening to permit flo-W in one direction and closing in the opposite direction to conne the flow through said restricted opening against the resistance offered by said strip.

8. In a fluid i'low shock absorber, the combination of a casing, a piston having an opening therethrough reciproc-able in said casing, a valve disk having a yieldable flap covering said piston opening with a restricted opening communicating with said piston opening and disposed within the margin of said iiap, a second valve disk cooperating with the opposite end of said piston opening and having an opening communicating with said piston opening and bridged by a yieldable strip, a third valve disk cooperating With said second valve disk and having a flap covering said second disk opening and a restricted opening covered by said strip, the ap of said rst valve disk and the flap ofsaid third valve disk closing and opening, respectively, during the yielding movement of the vehicle spring to thereby conne the fluid ilow through the restricted opening of said first Valve disk, and said ilap of said first valve disk and said flap of said third valve disk opening and closing, respectively, during the rebound movement of the vehicle spring to thereby confine the iluid flow through the restricted opening oi said third valve disk against the resistance offered by said yieldable strip.

9. In a fluid iiow shock absorber, valve means comprising a, pair-df cooperating valve members, one of said members having a yieldable portion provided with a restricted opening therethrough and the other of said members having a passage therethrough larger than said restricted opening and a yieldable member bridged across said passage to cover said restricted opening, said yieldable portion being movable ingan opening direction by a fluid pressure established on one side of said valve means operating through said passage to permit a flow therethrough and returnable to a closed position by a fluid pressure established on the opposite side of said valve means to permit a smaller ow through said restricted opening against theresistance offered by said yieldable member.

y1l). In a fluid flow shock absorber, the combination of a valve member having a central opening bridged by a yieldable part, a secondlvalve member coo-perating with said rst v-alve member having a yieldable portion covering said opening and a restricted opening covered by yieldable part, said yieldable portion openingto permit flow in one direction and closing in the opposite direction to confine the iiow lthrough said restricted opening against the resistance oiered by said yieldable part.

11. In a fluid flo-w shock absorber, the combination of a casing, a shiftable member having an opening therethrough mounted in said casing, a valve member having a yieldable portion larger than said opening with a restricted opening therethrough communicating with the opening in said shiftable member, a second valve member disposed adjacent said rst valve member and having an opening communicating with the opening in said shiftable member and bridged by a yieldable part, a third valve member cooperating with said second valve member and having a yieldable portion larger than the opening in said shiftable member and a restricted opening covered by the yieldable part in said second valve member, the yiel-dable portions on said first and third valve members closing and opening, respectively, during the yielding movement of the vehicle spring to thereby confine the fluid flow through the restricted opening of said first valve member, and said yieldable portions opening and closing, respectively, during the rebound mo-vement of the vehicle spring to thereby coniine the fluid flow through the restricted opening of said third valve member against the resistance offered by the yieldable part of said second valve member.

l2. In a iluid flow shock absorber, valve means comp-rising rst and second cooperating disk members, and a third disk member associated therewith, said rst member having a yieldable portion provided with a restricted opening therethrough and said second member being cutout Within its margin to provide a passage therethrough larger than said restricted opening and -a yieldable vstrip bridged between the opposite sides of said passage to cover said restricted opening, and said third member having a yieldable portion provided with a restricted opening disposed Within the margin of said portion, the yieldable portions of said first and third members opening and closing, respectively, during the yielding movement of the vehicle spring to thereby confine the fluid iiow through the restricted opening of said third member, and the yieldable portions of said first and third members closing' and opening, respectively, during the rebound movement of the vehicle spring to thereby confine the iluid ow through the restricted opening of said first member against the resistance offered by said yieldable strip.

13. In a uid flow shock absorber, valve means comprising first and second cooperating valve disks, and a third valve disk associated there- With, s-aid rst disk having a flap including a restricted opening therethrough cut from within the margin of the disk and joined thereto by a connecting segment, said seco-nd disk being cut out within its margin to provide a passage therethrough larger than said restricted opening and a yieldable strip bridged between the opposite sides of said passage to cover said restricted opening, and said third disk h-aving a flap including a restricted opening therethrough cut from within the margin of the disk and joined thereto by a connecting segment, the iiaps voli' said firstand third disks opening and closing,

respectively, during the yielding movement of the vehicle spring to thereby coni-lne the fluid flow through the restricted opening of said third disk, and the flaps of said rst and third disks closing and opening, respectively, during the rebound movement of the vehicle spring to thereby confine the iiuid ilow through the restricted opening of said rst disk against the resistance offered by said yieldable strip.

14. In a fluid oW shock absorber, the combination of a support having a passage therethrough and a shell portion provided with a groove, a valve member seated on said support within said shell portion and having a. yieldable part covering said passage and a restricted opening within the margin of said part communicating with said passage, said part opening to permit flo-W in one direction and seating in the opposite direction against said support to confine the flow through said restricted opening, and a spring for maintaining said member seated against said support, a coil of said spring being receivable in said groove to maintain said spring in position.

l5. In a uid flow shock absorber, a valve structure comprising a pair of disks of resilient material in contact with each other, one of said disks being cut out to form a resilient flap having a perforation therein and the other of said disks having an opening in registry with the flap of the first mentioned disk and an integral member eX- tending into said opening and registering with [tihe p :oration in the ap of the first mentioned isk.

i5. In a fluid flow shock absorber, a valve structure comprising a pair of disks in contact with each other, one of said disks having an internal flap with a perforation therein and the other of said disks having an opening in registry with said flap and a bridge member in registry with the perforation in said iiap.

17. In a fluid iiow shock absorber, a. valve structure comprising a pair of thin contacting valve members composed of resilient material, one of said members having a passage therethrough and being movable to an open position in response to pressure on one side of said structure, and the other or said members covering said passage in seating relation to said first named member and movable to an open position when pressure is established on the opposite side of the vave structure to thereby move said first named member to a closed position.

18. In a fluid ilovv shock absorber, the combination of a casing, a piston having an opening therethrough reciprocable in said casing, and a valve structure carried by said piston comprising a first valve member covering said piston opening and having a passage therethrough for communicating with'said piston opening, and a second valve member, said members being composed of thin resilient material and located to place said second member in closing relation` to said passage, pressure on one side of the valve structure established by a movement of the piston moving said first member away from its associated seat and pressure on the opposite side shifting said first member to a closed position and said second member to an open position to permit flow through said passage against the resistance of said second member.

i9. In a fluid flow shock absorber, a valve structure comprising a pair of plate members in face to face surface contact with each other, one of said members having an opening therethrough and being movable from a closed position to an open position in response to fluid pressure on one side of said structure and the other of said members having a portion thereof covering said opening and movable to an open position by pressure on the opposite side of said structure which acts through said opening and which tends to: move said one member to its closed position.

20. In a fluid flo-w shock absorber, a' valve structure comprising a pair of plate members in contact with each other, one of said members having an opening therethrough and being movable from a closed position to an open position. in response to fluid pressure on one side of said structure and the other of said members being a' disk having a thin flexible portion covering said opening and adapted to be flexed to open position by pressure on the opposite .side of said structure which acts through said opening and which moves said one member to its closed position.

2l. In a fluid flow shock absorber, the combination of a part having a passage therein and a seat around said passage, and a valve structure contro-lling said passage, said structure comprising a pair of plate members in contact with each other, one of said members having an opening therethrough and being movable away from said seat in response to fluid pressure on one side of the structure and the other of said members having a portion thereof covering said opening and movable away from said one member by fluid pressure on the opposite side of said structure acting through said opening.

22. In a fluid flow shock absorber, the combination of a part having a fluid passage therein, a valve structure for controlling said passage comprising a pair of plate members in face to face surface contact with each other, one member having an opening therein and the other member being a disk having a flexible portion overlying said opening to control the same, and a seat on said part with which said structure cooperates, whereby fluid pressure acting on one side of the structure causes said one member to bev moved to an open position and fluid pressure acting subsequently on the other side of the structure causes said one member to be moved to its closed position while said flexible portion is sprung away from said opening by the fluid acting therethrough. Y

23. In a fluid flow shock absorber, the combination of a movable piston having a passage therethrough and a seat around saidpassage, and a valve structure controlling said passage, said structure comprising a. pair of plate members in contact with each other, one of said members having an opening therethrough and being movable away from said seat in response to fluid pressure on one side of the structure andthe other of said members having a portion thereof covering said opening and movable away from said one member by fluid pressure on the opposite side o-f said structure acting through said opening.

24. In a fluid flow shock absorber, the combination of a movable piston having a fluid passage therethrough, a valve structure for controlling said passage comprising a pair of plate members in face to face surface contact with each other, one member having an opening therein and the other member being a disk having a flexible portion overlying said opening to control the same, and a seat on said piston with which said structure cooperates, whereby fluid pressure acting 'on one side of the structure causes said one member to be moved to an open position and fluid pressure acting subsequently on the other sideof the structure causes said one member to be moved to its closed position while said flexible portion is sprung away from said opening by the fluid acting therethrough.

25. In a double acting, fluid flow shock absorber of the vehicle type, the combination of a fluid-containing chamber, a piston operable in said chamber in response to up and down movements of the vehicle wheels for subjecting the fluid to pressure, meansproviding a transfer passage through which fluid is displaced by operation of the piston, and flow control means associated with said passage for regulating the transfer of fluid therethrough, said control means including means for restricting the transfer of fluid through said passage in one direction and a Valve plate having a relatively thin flexible part adapted to function as a check valve element, said flexible part having an opening therein for restricting the transfer of fluid through said passage in the opposite direction.

26. In a double acting, fluid flow shock absorber of the vehicle type, the combination of a fluidcontaining chamber, a piston operable in said chamber in response to up and down movements of the vehicle wheels for subjecting the fluid to pressure, said piston having a transfer passage through which fluid is displaced by operation of the piston and flow control means associated with said piston passage for regulating the transfery of fluid therethrough, said control means including means for restricting the transfer of fluid through said passage in one direction and a valve plate having a relatively thin flexible part adapted to function as a check valve element, said flexible part having an opening therein for restricting the transfer of fluid through said passage in the opposite direction.

27. In a fluid flow shock absorber, the combination of a support having a passage therein and a Seat associated with said passage, means operable to displace fluid through said passage, and a valve disk associated with said support and having a yielda-ble flap provided with a restricted opening therethrough, said flap being adapted to be moved away from said seat by a flow of fluid in one .direction through said passage and adapted to be moved against said seat by fluid pressure on the other side of the valve disk whereby the flow in the opposite direction is restricted solely by said opening.

28. In a fluid ow shock absorber, the combination of a housing having a fluid-containing chamber therein, a piston operable in said housing for subjecting the fluid to pressure, said piston having a transfer passage through which fluid is displaced by operation of the piston and a seat associated with said passage, and a valve disk on said piston having a yieldable flap provided with a restricted opening therethrough, said flap being movable away from said seat by a flow of fluid through said passage in one direction and adapted to be moved against said seat by fluid pressure on the other side of the valve disk whereby the flow in the opposite direction is restricted solely by said opening,

29. In a fluid flow shock absorber of the vehicle type, the combination of a fluid-containing chamber, a piston operable in said chamber in response to up and down movements of the vehicle wheels for subjecting the fluid to pressure, means providing a transfer passage through which fluid is displaced by operation of the piston, and flow control means associated with said passage for regulating the transfer of fluid therethrough in one direction comprising a pair of plate members ink face to face surface contact with each other, one of said membersl having. an

opening therethrough and the other member having a portion covering said opening and movable to an open position by pressure operating through the opening to thereby connect the opening and passage.

30. In a fluid flow shock absorber of the vehicle type, the combination of a fluid-containing chamber, a piston operable in said chamber in response to up and dovvnv movements of the vehicle wheels for subjecting the iiuid to pressure, means providing a transfer passage through which fluid is displaced by operation of the piston, and flow control means associated withl said passage for regulating the transfer of fluid therethrough in one direction comprising a pair of plate members in contact with each other, one of the members having an opening therethrough and the other member having a thin exible portion covering said opening` and adapted to be exed to open position. by pressure operating through the opening to thereby connect the opening and passage.

3l. In a iiuid flow shock absorber, valve means comprising a structure having nrst and second plate members in face to face surface contact with each other, and a third plate member associated therewith, said first member having an opening therethrough and being movable from a. closed position to an open position in response-to fluid pressure on one side of said structure and said second member having a portion thereof covering said opening and movable to an open position by pressure on the opposite side of said structure which acts through said opening and which tends to move said rst member to its closed position, and said third member having a restricted opening disposed within the margin thereof and movable from a closed position to an open position in response to iluid pressure on one side thereof, said first and third members opening and..

closing, respectively, during the yielding movement of the vehicle spring to thereby confine the uid flow through the restricted opening of saidl third member, and said first and third membersy closing and opening, respectively, during the rebound movement of the vehicle spring. to thereby coniine the fluid, flow through the openingv of said irst member against the resistance offered' by said second member. v

32. In a fluid flow shock absorber, valvemeans comprising a structure having rst and second plate members inv contact with each other, and a third plate member associated therewith, said first member having an opening therethrough and being movable from a closed to an open position in response to fluid pressure on one side of said structure and the said second member having a thin flexible portion covering said open-` ing and adapted to be iiexed to open position by pressure on the opposite side of said structure which acts through said opening and which moves said first member to its closed position, and said third member having a restricted opening therethrough and being movable from a closed positionl to an open position in response to fluid pressure on one side thereof, said rst and third members opening and closing, respectively, during. the yielding movement of the vehicle spring to` thereby confine the uid flow through the restricted opening of said third member, and said rst and third members closing and opening, respectively, during the rebound movement .of the vehicle spring to thereby confine the fluid flow through the opening of said first member against the resistance oiered by said exible portion.

33..In. a fluid flow shock absorber, the combination of. a support having a passage through which fluid isl moved and a seat associated with said passage, anda valve structure comprising a pair of plate members associated with said support, one of said members having an opening therethrough and being movable away from the other member in response to iiuid pressure on one side of the structure .and said other member having a yieldable portion associated with said, opening and movable to an open position by pressure on the opposite side of said structure.

which` acts through said opening and which tends to move said one member to its closed position.

34..In. a fluid ow shock absorber, the combination of a. support having a passage through which uid is moved and a seat associated with said passage, and a valve structure comprising a pair of plate members associated with said support, .one of said members having an opening therethrough and being movable away from the other member inv response to fluid pressure on one side of the structure and said other member having a thin flexible portion associated with said opening and adapted to be flexed to open posltionby pressure on the opposite side of said structure which acts through said opening and which movessaid one member to closed position.

DENNIS B. D. BLAKE. 

